Electronic tube



Sept. 19, 1950. I H. A. ZAHL 2,522,557

ELECTRONIC TUBE Filed. Jan. 25, 1945 a Sheets-Sheet 1 FIG.

INVENTOR HAROLD ZAHL BY I ATTORNEY Sept. 19, 1950 Q H. A. ZAHL ELECTRONIC TUBE Filed Jan. 25, 1943 3 Sheets-Sheet 2 Fl G. 5

FIG 4 FIG. 8

F I c. 7

Ila

INVENTOR HAR A TTORNE Y H. A. ZAHL ELECTRONIC TUBE Sept. 19, 1950 3 Sheets-Sheet 3 Filed Jan. 25, 1943 FIG. l4

FIG. l5

'FIG. l6

[NI/[1N TOR HAROLD A.ZAHL

A '1 TOR N15 Y Patented Sept. 19, 1950 ELECTRONIC TUBE Harold A. Zahl, Long Branch, N. J.

Application January 25, 1943, Serial No. 473,556

26 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 19.28; 37d 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to electronic tubes, and more particularly to such tubes intended to work at ultra high frequencies.

The primary object of my invention is to generally improve oscillation generators for ultra high frequency work. Considered in a somewhat different aspect, the primary object of my invention is to improve electronic tubes used with ultra high frequencies.

Some more specific objects of my invention are to devise an oscillator having short, direct, efficient power connections between its oscillating circuit (tank circuit) and the electrodes of the tube; to enclose multiple electrode assemblies for push pull operation and their associated tuned circuit elements all within a single evacuated envelope; to provide an oscillator tube of this character having a high breakdown resistance so that the tube may be subjected to large driving voltages; to provide extensive cooling surfaces for the anode and grid circuits, the latter being used as heat radiating surfaces for the anodes and grids; to provide an oscillator of the described character in which the structural parts are arranged symmetrically for increased strength and rigidity; to provide such a tube in Which the power supply and take 01f leads to the electrodes act also as the physical supports for the electrodes and tuned circuit elements; to so arrange the said leads as to provide generous spacing between leads of different character; and to provide a tube in which the usual limitation of maximum output due to the limited cathode area of a filamentary cathode is overcome by the provision of multiple cathodes acting in parallel.

To the accomplishment of the foregoing objects and such other objects as will hereinafter appear, my invention consists in the electron tube and oscillator elements, and their relation one to the other, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

Figure 1 is a front elevation of an oscillator tube embodying features of my invention;

Figure 2 is an end elevation thereof;

Figure 3 is a plan view of the anode circuit structure;

Figure 4 is a front elevation thereof;

Figure 5 is an end elevation thereof;

Figure 6 is a plan view of the grid circuit structure;

Figure 7 is a front elevation thereof;

Figure 8 is a section taken in the plane of the line 88 in Fig. 7; f

Figure 9 is an elevation showing the cathode and its support wires; v

Figure 10 is a section through one of the anode leads and supports;

Figures 11, 12 and 13 are schematic diagrams explanatory of the invention;

Figure 14 is a schematic diagram showing how the oscillator tube of my invention is externally wired or energized; and

Figures 15 and 16 are schematic diagrams explanatory of one theory of operation of the tube.

The general arrangement of my improved oscillator tube may be described with preliminary reference to Figures 11, 12 and 13 of the draw ing. Referring first to Figure 11, the oscillator comprises anodes I2 and I4 directly connected by an anode circuit l 6. This is preferably a wide metal band bent to U shape, its length being suitably selected to provide electrical resonance (together with the inductance and capacitance of the other tube parts) at the desired oscillation frequency. The anodes l2 and M are at instan; taneous opposite polarity and function in push pull. The cathodes are indicated at I 8 and 20, and the electron flow therefrom is controlled by the grids 22 and 24 respectively. These grids are directly connected to the grid circuit 26. This is also preferably U or trombone shaped, like the anode circuit IS. The grid and anode circuits are regeneratively coupled.

In accordance with my invention the electrodes for both tubes of the push pull circuit are located within a single tube envelope. Moreover, the anode and grid circuits It and 26 are also located within the tube envelope, so that the circuits may be connected directly to the electrodes with no intervening lead Wires.

The manner in which the elemental oscillator elements of Figure 11 are enclosed within a tube envelope and are externally energized can be understood with reference to Figure 14, in which the tube envelope is schematically represented by a broken line 28. The grids are biased by means of potential applied to the lead 30, which is most conveniently connected to the outer or remote end ofthe grid trombone 26. Thus the direct current grid bias is applied to a radio frequency potential node, and the lead wire may be widely spaced from the other lead wires of the tube. The anodes are connected to leads 32 and 34, which in turn are connected to a suitfili able transmission line or antenna. In the present case the antenna is represented by dipole 36;

J For impedance matching purposes, the leads 32 and 34 are symmetrically arranged and are connected by an adjustable shorting bar 38. The direct current anode potential may be connected to the shorting bar 38, or may be connected as indicated at 46.

For work at the ultra high frequencies here contemplated, the filament leads are preferably tuned. This is schematically illustrated in Figure I4 in which the cathode leads 42 and 44 are connected by an adjustable shorting bar 4-6. The connection 48 may be grounded if the tube is worked with plate or grid keying, or it may be connected to a source of high negative potential if the tube is worked with cathode keying, in which case the anode lead 46 may be grounded.

The theory of filament tuning is viewed in various ways, for example, as being to prevent radio frequency leakage and undesired radiation; or to provide a connection of zero radio-frequency potential diiference between the cathodes, in order to anchor the same with respect to radio-frequency oscillations of the grid and anode; or to accommodate or match the impedance otherwise existing between the cathodes. In the present case there is the added advantage of modifying or adjusting the operating frequency of the oscillator. For practical purposes the theory is not too important, because the shorting bar 46 is simply adjusted until the cathode leads are tuned for good output at the desired frequency.

Referring now to Figure 12 of the drawing, the structure shown in Figure 11 may be made symmetrical by providing an anode circuit 50 identical with the anode circuit I6 but extending in opposite direction. The trombones are connected end to end and to the anodes. Similarly, the grid circuit 26 previously referred to, is duplicated by an oppositely directed grid circuit '52, and both grid. circuits are connected in common to the grids.

The power output of the tube as so far described may be limited by the available cathode emission, or cathode area, particularly when using filamentary cathodes. In such case the available power output may be doubled by using two sets of electrodes (or so called barre1s,) in parallel or shunt with one another, on each side of the push pullcircuit. Such an arrangement is schematically illustrated in Figure 13, in which it will be seen that anode circuit 54 is directly connected to anodes 56 and 58; while anode circuit 60 is directly connected .to anodes 62 and 64. From one viewpoint it may be said that the anodes on each side are connected together. From another viewpoint it may be said that the ends of the trombones are connected together, and that the anodes are secured on the connected trombones. Similarly, the grid circuit 66 is connected to grids 68 and I while the grid circuit I2 is connected, to the grids I4 and 76. Here again it may be said that either the grids or the ends of the grid .trombones are connected together.

With the foregoing preliminary explanation in mind, the tube structure illustrated in Figures 1 thru of the drawing will be readily understood. The anode to anode circuit structure is separately illustrated in Figures 3, 4, and 5. Referring to these, it will be seen that cylindrical anodes 80 and 82 are arranged parallel to one another and are connected to one another and to the adjacent ends-of anode circuits 84 and 86. The anodes 80 and 82 operate in push pull relation to anodes 88 and90, which are connected to one another and to the opposite ends of the trombones ,84 and .86.-

The entire anode structure is preferably made of a suitable high temperature metal such as tantalum, although other metals, for example molybdenum, may also be used.

From Figures 4 and 5 it will be seen that the anode circuits are relatively massive. This is not only to carry high radio frequency current but also because the trombones function as effective heat radiators to aid heat dissipation from the anodes.

This heat dissipation may be increased by the provision of fins 92, which in the present case extend axially of the anodes, and project radially therefrom.

The cylindricalanodes are mounted in supports or pieces of sheet metal 94 bent outwardly to form a top 96 and bottom 98. The ends of the trombones are secured, as by spot welding, to the vertical'wall 94. The horizontal walls 96 and 98 are apertured to receive the cylindrical anodes. The fins 92 are made of sheet metal bent to trough ,or channel shape, so that each piece of metal forms two fins with aconnecting portion adapted to be welded to the outside of the anode, between the tQpand bottom walls 96 and 98. If desired, tabs of metal may be turned inwardly at the top and bottom of the fins, as shown.

The grid circuit structure is best shown in Figures 6, 7, and 8, referring to which it will be seen that each grid is substantially cylindrical in configuration, and is made up of vertical wires I00 reinforced by circular binding wires I02. The vertical wires are preferably made in pairs, each pair being reversely bent or shaped like a hairpin, with the closed end at the top, the latter end being bent inwardly to close the top of the grid, as is best shown at I04 in Figure 6. The lower ends of the grid wires are spot welded around a short metal cylinder I06. There are four such cylindrical ,grid structures, and these are suitably spaced to fit concentrically within the four anodes previously described.

The grid circuits or trombones are shown at I08 and I I0. These are made of relatively thin sheet metal, such as tantalum, the metal being flanged inwardly at the top and bottom. In other words the metal is channel shaped, thus stiffening the structure, despite the thinness of the metal used. (Flanged metal may also be used for the anode trombone.) If desired, both grid trombones may be made of a single strip of metal bent to form the complete structure which, in the present case, comprises parallel sides joined by circular ends H8 and I26. While not really elliptical, this structure is sometimes hereinafter referred to, for convenience, as being approximately elliptical. In the present case, the ends of the channel shaped strip are joined at one end of the elliptical structure, as shown at I22, this being convenient because the ends have added thereto strips I24 forming ears I26 for receiving the support leads.

The grids are mounted on the grid circuit structure by means of outwardly bent strips I28 and I36. The fiat portions of these strips are welded to short intermediate channels I I4 and I I6, while the outwardly bent loops pass closely around and are welded to the cylinders I86 at the lower end of the grids.

The cathode structure is illustrated in Figure 9. In the present case the cathode is of the directly heated or filamentary type, it comprising oppositely wound helical wires I32 and I34. These are supported at the top by means of a central support wire I36. The lower ends of the filament are connetted to current supply leads I38 and I40. The three wires I36, I38 and I40 are embedded in a glass bead I42. The lead Wires are spread apart and pass through a glass bead I44 which subsequently forms a part of the seal for the lead in. The filament may be made of a suitable emissive material such as thoriated tungsten, and the lead wires may be made of tungsten 'or other metal which will seal well to glass.

Referring now to Figures 1 and 2 of the drawing, the parts so far described are housed within a suitable envelope I50. This may be made of glass, and is preferably highly evacuated, the vacuum pump having been connected at a suitable tubulation point I52. The glass envelope I50 is generally cylindrical, with approximately hemispherical ends I54. The diameter of the cylindrical envelope is somewhat larger at the central portion I56, thus better accommodating the anodes, but if desired the entire envelope may be made at the large diameter.

The lead and support wires of the four cathodes pass through four outwardly directed glass stems I58. The glass beads I44 previously referred to may be made of a special glass (such as that known commercially as No-Nex) which will seal properly to the wire and which will minimize problems of unequal temperature expansion.

The grid circuits I08 and H0 are supported by wires I60, the upper ends of which are secured in the ears I26 previously referred to, and the lower ends of which pass through stems I62 and seals I64. Only one of these wires is needed to supply grid bias potential, and if desired one wire may therefore be terminated within its glass bead. However, both are preferably passed through the glass beads for symmetry, and for convenience in being able to connect the grid bias at either end of the tube. It will be noted that with the arrangement shown, the connection to the grid circuit is at a radio-frequency potential node. Moreover, the leads for the grid circuit are Very widely spaced from the leads for the cathodes.

The anode circuits 84 and 86 are supported by means of rigid supports or leads I 66 and I68 which pass upwardly through stems I10 and are sealed at glass beads I 72. The detailed construction of the leads I66 and I68 will be clear from the section therethru shown in Figure 10. The lead comprises a solid portion I14 made of molybdenum or other suitable high temperature metal. The upper part of the lead is a tube I'I6 preferably made of Kov-ar or other suitable metal having the same temperature coefficient of expansion as glass. The upper end of tube I16 may be closed by means of a plug I78 which is preferably brazed in position, vacuum tight. The lower end of the lead is reduced in diameter at I80, and threaded at I82 for connection to the anode structure.

Referring to Figure 3, the top walls 96 are perforated at I84 to receive the anode lead. An internally threaded boss or nut I86 (Fig. 4) is secured in place, as by welding, to the lower walls 98 of the anode assembly. Reverting now to Figure 1, it will be seen that the lower end of the lead I66 passes through the top of the anode assembly and is received in the boss I86.

Power is delivered from the oscillator through leads I66 and I68 in the manner schematically shown in Figure 14, the corresponding leads being there marked 32 and 34. The leads are relatively rigid and are preferably large in diameter in order to sturdily support the anode structure against vibration. The leads may be made tubular because the output is at very high frequency.

These leads serve also for direct current supply to the anodes.

The oscillation frequency is deter-mined primarily by th physical dimensions of structure of the anode and grid circuits. These circuits are so designed and selected as to produce substantially the desired operating frequency, say 600 megacycles. (I have also made tubes of the type here shown which operate at 400 megacycles and others at 200 megacycles.) However, a slight degree of external control of the frequency is desirable in order to adjust the frequency of the finished tube to exactly the desired value, and this may be provided by varying the tuning of the external circuits, particularly the filament circuit. Referring to Figure 14, the tuning provided by the shorting bars 38 and 46 may be used within small limits, say 10 meg-acycles, to control the frequency of the complete oscillator. This is convenient as a practical matter, for once the tube has been evacuated and sealed there would otherwise be no way of regulating its frequency. In practice the cathode tuning controls the frequency, but permits two different frequencies or modes of vibration. The anode tuning may be used to select either of the two frequencies. The power output changes only slightly when tuning within small limits as here suggested. The final frequency depends also to some extent on the antenna tuning or load. This should be present for final adjustment.

I have not worked out in mathematical detail the exact theory of operation of the oscillator tube disclosed herein. The tube operates very successfully with design dimensions worked out largely by empirical treatment.

The simplest explanation of the operation of the tube is to assume that it consists of an anode circuit I6 (Figure 11) which, together with the reactances of the associated tube electrodes, leads, etc., is resonant at the desired frequency, and that similarly the grid trombone 26 and its associated reactances are resonant at the desired frequency, these two resonant circuits being regeneratively coupled. In such case the anodes I2 and I4 are at opposite polarity, the grids 22 and 24 are at opposite polarity, the anode I2 and grid 22 are at opposite polarity, and the grid 24 and anode I4 are at opposite polarity, all as they should be. The magnetic coupling between the trombones will produce or will be consistent with the necessary reversal of polarity between the electrodes. The physical length of the trombone works out to be much smaller than, say about one-half of the theoretical length. The difference is presumably due to associated interelectrode capacitance. Oscillation is also aided by the interelectrode capacitance.

An alternative mode of current flow in the tube may be explained with reference to Figures 15 and 16 of the drawing. Referring to Figure 15, a resonant circuit may be considered as made up of a grid trombon 226 and an anode trombone 2I6, these being connected by capacitances 200 and 202, provided mainly by the grid to plate capacitances of the tube. The arrows show instantaneous current flow. In Figure 16 the circuit of Figure 15 has been rearranged to bring the grid trombone 226 beneath the anode trombone 2I6. On reflection it will be seen that the direction of current flow is still proper for magnetic regenerative coupling. The rearranged circuit shown in Figure 16 would explain the operation of the tube if single trombones were used, as shown in Figure 11, instead of the dual or symmetrical :trombones shown in Figure 12. With the arrangement of Figure 12 it is not necessary to assume that the grid circuit is folded back beneath the anode circuit, for instead (referring to Figure 12) the anode trombone l6 and grid trombone 52 may be considered as making up one resonant circuit, while the anode trombone 50 and grid trombone 26 may be considered as making up another similar resonant circuit. I have found that there is some parasitic oscillation in the alternative paths here described.

It will be understood that the aforegoing discussion of possible theories of operation of the tube are ofiered merely by way of explanation, and not in limitation of the invention, which instead may be predicated on empirical work leading to very successful operation.

The leads 166 and IE8 (Figs. 1 and 2) being directed upwardly are remote from the other leadsthus providing very good breakdown resistance inside the tube, so that it is possible to use high driving Voltages for the tube. It will also beseen that the connections between the anodes and the anode trombone are as direct as possible, being in fact of zero length. Moreover, the connections are large efficient connections. Similar remarks apply to the grid circuits. In both the grid and anode structures the circuits act as large area radiating surfaces for dissipating heat from the grids and anodes.

It is believed that the construction and opera tion of my improved oscillator tube, as well as the many advantages thereof, will be apparent from the foregoing detailed description. The tube provides a substantially complete oscillator nearly all of the parts of which are enclosed within the tube envelope. The unit is therefore a very compact one, yet is capable of high power output. For example, a tube of this type designed togenerate oscillations at 600 megacycles, is capable of a peak power output of about 200 kw. when keyed in short pulses. For this output a blower is preferably used to cool the tube.

It will be understood that while I have shown and described my invention in a preferred form, many changes and modifications may be made in the structure disclosed, without departing from the spirit of the invention as sought to be defined in the following claims.

I .claim:

1. A tube comprising an envelope having there in two spaced collaterally disposed cathodes, grids and anodes adjacent to said cathodes, an anode toanode resonating circuit inside said envelope, the ends of said anode circuit being connected directly to said anodes, a grid to grid circuit inside said envelope, the ends of said grid circuit being connected directly to said grids, rigid anode leads extending directly from said anodes approximately in the direction of the axes of the anodes through said envelope on one side, cathode leads extending approximately in the direction of the axes of the cathodes through said envelope on the side opposite said anode leads, and a grid lead extending from said grid I a grid to grid resonating circuit inside said envelope, the ends of said grid circuit being con-' nected directly to said grids, said anode and grid circuits being suitably juxtaposed for regenerative coupling, rigid anode leads extending directly from said anodes approximately in the direction of the axes of the anodes through said envelope on one side, cathode leads extending approximately in the direction of the axes of said cathodes through said envelope on the side opposite said anode leads, and a grid lead extending from the center of said grid circuit through said envelope at a point remote from said anode and cathode leads, said leads constituting the structural supports for all of said tube elements.

3. An oscillator tube for ultrahigh frequencies comprising an evacuated glass envelope having therein two spaced collaterally disposed cathodes, control grids and anodes adjacent to said cathodes, a U-shaped anode to anode circuit inside said envelope, the ends of said anode circuit being connected directly to said anodes, a U- shaped grid to grid circuit inside the envelope, the ends of said grid circuit being connected directly to said grids, relatively rigid anode leads extending directly from said anodes in the direction of the axes of said anodes through said envelope on one side, cathode leads extending in the direction of the axes of said cathodes through said envelope on the side opposite said anode leads, and a grid lead extending from the center of said grid circuit through said envelope at a point remote from said anode and cathode leads, said leads constituting the structural supports for said tube elements.

4. A tube comprising an envelope, two spaced cathodes, control grids and anodes adjacent to said cathodes, two oppositely directed circuits inside said envelope, each of said circuits having a pair of ends connected directly to said respective anodes, another pair of oppositely directed circuits inside the envelope, each of said latter circuits having a pair of ends connected directly to said respective grids, and leads extending outwardly from the aforesaid elements through said envelope.

5. An oscillator tube, said tube comprising an envelope, two spaced cathodes, grids surrounding said cathodes, anodes surrounding said grids, two oppositely directed anode to anode circuits inside said envelope, the ends of each of said respective circuits being connected directly to said anodes, another pair of oppositely directed circuits inside said envelope, the ends of said latter circuits being connected directly to said grids, the grid and anode circuits being disposed in regeneratively coupled relation to one another, and leads extending outwardly from the aforesaid elements through said envelope.

6. An oscillator tube for ultra high frequencies, said tube comprising an evacuated glass envelope, .two spaced cathodes, control grids and anodes adjacent thereto, two oppositely directed U- shaped grid to grid circuits inside the envelope, the ends of said circuits being connected directly to the grids, and leads extending outwardly from the aforesaid elements through the envelope of the tube.

'7. An oscillator tube for ultra high frequencies, said tube comprising an evacuated glass envelope, two spaced cathodes, control grids and anodes adjacent thereto, two oppositely directed U- shaped anode to anode circuits inside said envelope, the ends of said anode circuits being connected directly to said anodes, another ,pair of oppositely directed U-shaped grid to grid circuits inside said envelope, the ends of said grid circuits being connected directly to said grids, the grid and anode circuits being disposed in regeneratively coupled relation to one another, and leads extending outwardly from the aforesaid elements through said envelope.

8. A tube comprising an envelope, two spaced cathodes, grids and anodes adjacent thereto, two oppositely directed anode-to-anode circuits inside said envelope, the ends of said anode circuits being connected directly to said anodes, another pair of oppositely directed circuits inside the envelope, the ends of said latter circuits being connected directly to said grids, a pair of relatively massive rigid anode leads extending from said anodes through the side of said envelope, cathode leads extendin in the direction of the axes of said cathodes through the side of said envelope, and grid leads extending from said grid circuits through said envelope.

9. A tube comprising an envelope, two spaced collaterally disposed cathodes, grids surrounding said cathodes, anodes surrounding said grids, two oppositely directed anode-to-anode circuits inside said envelope, the ends of said anode circuits being connected directly to said anodes, another pair of oppositely directed circuits inside said envelope, the ends of said latter circuits being connected directly to said grids, a pair of rigid anode leads extending in the direction of the axes of said anodes through one side of said envelope, cathode leads extending in the direction of the axes of said cathodes through the side of said envelope opposite said anode leads, and grid leads extending from said grid circuits through the sames side of said envelope through which said cathode leads extend.

10. An oscillator tube for ultra high frequencies, said tube comprising an evacuated glass envelope, two spaced collaterally disposed cathodes, grids and anodes adjacent thereto, two oppositely directed U-shaped anode-toanode circuits inside said envelope, the ends of said anode circuits being connected directly to said anodes, another pair of oppositely directed U-shaped circuits inside said envelope, the ends of said latter circuits being connected directly to said grids, said grid and anode circuits being disposed collaterally in regeneratively coupled relation to one another, a pair of rigid anode leads extending in the direction of the axes of said anodes through one side of said envelope, cathode leads extending in the direction of the axes of said cathodes through the side of said envelope opposite said anode leads, and grid leads extending from the outer ends of said grid circuits through the same side of the envelope through which said cathode leads extend.

11. A tube comprising an envelope, four spaced cathodes, four grids and. anodes adjacent thereto, two oppositely directed anode-to-anode circuits inside said envelope, the ends of one of said anode circuits being connected directly to one pair of said anodes and the ends of the other of said anode circuits being connected directly to the other pair of said anodes, said anode circuits being connected end to end, another pair of oppositely directed circuits inside said envelope, the ends of one of said latter cir cuits being connected directly to one pair of grids, the ends of the second of said latter cir cuits being connected directly to the other pair of said grids, said latter grid circuits being connected end to end, anode leads extending from the junctions of said anode circuits through the side of said envelope, cathode leads extending through the side of said envelope, and grid leads extending through the side of said envelope.

12. A tube comprising an envelope, four spaced collaterally disposed cathodes located at the, corners of a rectangle, four grids surrounding said cathodes, four anodes surrounding said grids, two oppositely directed anode-to-anode circuits inside said envelope, the ends of one of said anode circuits being connected directly to one pair of said anodes and the ends of said other anode circuit being connected directly to the other pair of said anodes, both of said anode circuits being connected end to end, another pair of oppositely directed grid to grid circuits inside said envelope, the ends of one of said grid circuits being connected directly to one pair of said grids, the ends of the second of said grid circuits being connected directly to the other pair of said grids, said grid circuits being connected end to end, a pair of relatively rigid anode leads extending from the junctions of said anode circuits in the direction of the axes of the anodes through one side of said envelope, cathode leads extending in the direction of the axis of the cathodes through the side of the envelope opposite said anode leads, and grid leads extending from the grid circuits through the same side of the envelope through which said cathode leads extend.

13. An oscillator tube for ultra high frequencies, said tube comprising an evacuated glass envelope, four spaced collaterally disposed cathodes located at the corners of a rectangle, four grids surrounding said cathodes, four anodes surrounding said grids, two oppositely directed U-shaped anode-to-anode circuits inside said envelope, the ends of one of said anode circuits being connected directly to one pair of said anodes and the ends of the other of said anode circuits being connected directly to the other pair of said anodes, said anode circuits being connected end to end, another pair of oppositely directed U-shaped grid to grid circuits inside said envelope, the ends of one of said grid circuits being connected directly to one pair of said grids, the ends of the second of said grid circuits being connected directly to the other pair of said grids, said grid circuits being connected end to end, the grid and anode circuits being disposed collaterally in regeneratively coupled relation to one another, a, pair of relatively rigid anode leads extending from the junctions of said anode circuits in the direction of the axes of the anodes through one side of said envelope, cathode leads extending in the direction of the axes of the cathodes through the side of the envelope opposite the anode leads, and grid leads extending from the outer ends of the grid circuits through the same side of the envelope through which said cathode leads extend.

14. A tube comprising an elongated envelope having therein a pair of electron tube sections each comprising an anode, a cathode and a grid, an approximately elliptical circuit disposed inside said envelope in the direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to said first circuit, the anodes being secured directly to opposite sides of said first circuit, the grids being secured directly to the opposite sides of said second circuit, cathode leads extending from the cathodes through the side wall of said 11 envelope, grid leads extending from the remote ends of said grid circuit through said envelope, and anode leads extending from said anodes through said envelope.

15. An oscillator tube for generating ultra high frequencies, said tube comprising an elongated envelope having therein a pair of electron tube sections each having an anode, a cathode and a grid, an approximately elliptical circuit disposed inside said envelope in the direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to said first circuit in regeneratively coupled relation thereto, the anodes being secured directly to opposite sides of said first circuit, said grids being secured directly to the opposite sides of said second circuit, cathode leads extending from said cathodes transversely of said envelope axis through the side wall of the envelope, grid leads extending from said grid circuit through said envelope, and anode leads extending from said anodes through said envelope in a direction transverse to the envelope axis.

16. An oscillator tube for generating ultra high frequencies, said tube comprising a generally cylindrical, elongated, evacuated glass envelope, an approximately elliptical circuit disposed inside said envelope in the direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to said first circuit in regeneratively coupled relation thereto, an anode secured directly on the outside of each side of said first circuit, a grid disposed Within each anode, the ends of said grids projecting beyond said anodes and being secured directly to the sides of said second circuit, cathodes inside said grids, cathode leads extending from said cathodes, transversely of the envelope axis through the side wall of the envelope, grid leads extending from the remote ends of said second circuit through said envelope, and anode leads extending from said anodes through said envelope in a direction transverse to the envelope axis.

17. A tube comprising an elongated envelope,

an approximately elliptical circuit disposed inside said envelope in the direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to said first circuit, two anodes secured directly on the outside of one side of said first circuit, two similar anodes disposed on the other side of said first circuit, a grid disposed within each of said anodes, the ends of said grids projecting beyond said anodes, two of said projecting ends being secured directly to one side of said second circuit, the other two of said projecting ends being secured directly to the other side of said second circuit, cathodes inside said grids, cathode leads extending from said cathodes through the side wall of said envelope, grid leads extending from said second circuit through said envelope, and anode leads extending from said first circuit through said envelope.

18. An oscillator tube for generating ultrahigh frequencies, said tube comprising an elongated envelope, an approximately elliptical circuit dis posed inside said envelope in the direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to said first circuit in regeneratively coupled relation thereto, two adjacent collaterally disposed anodes secured directly on the outside of one side of said first circuit, two similar adjacent collaterally disposed anodes disposed on the other side of said first circuit, a grid disposed within each of said anodes, the ends of sai'dgrids projecting beyond said anodes,. two of said projecting ends being-secured directly to one side of said second circuit, the other two of said projectingv ends being secured directly to the other side of said second circuit, cathodes inside said grids, cathode leads extending; from said cathodes through the'side wall of said envelope, grid leads extending from said second circuit through said envelope, and anode leads extending from said anodes through saidenvelope.

19. An oscillator tube for generating ultra high frequencies, said tube comprising a generally cylindrical, elongated, evacuated glass envelope, an approximately elliptical circuit disposed inside said envelope in the; direction of the axis of said envelope, a second approximately elliptical circuit disposed generally parallel to saidfirst circuit in regenerativelycoupled relation thereto, two adjacent collaterally dise posed anodes secured directly on the outside of one side of said first circuit, twosimilar adjacent collaterally disposed anodes disposed on the other'side of said first circuit, a grid disposed within each of said anodes, the endsofsaid grids projecting beyond the anodes, two of said projecting ends being secured directly to one side of said second circuit, and the other two-of said projecting ends being secured, directly to the other side of said second circuit, cathodes inside said grids, cathode leads extending from said cathodes transversely of the envelope axis through the side wall of said envelope, grid leads extending from the remote ends of said second circuit through said envelope, and anode leads extending through said envelope at points remote from said cathode leads and in a direction transverse to the axis of said envelope.

20. An electronic tube comprising an envelope, a pair of plate electrodes disposed side-by-s'ide in the envelope, a plurality of fins interconnecting the electrodes and lying in planes transversely of and spaced along the electrodes,.a conductor means sealed to the envelope, and means unitarily supporting said electrodes on said conductor means.

21. An electronic tube comprising an envelope, a plurality of anodes in the envelope, heat radiating fins on said anodes, a grid adjacent each anode, anode conductor means projecting into the envelope, means supporting the anodes on said" conductor means, a grid circuit structure in the envelope, means supporting said grids on the circuit structure, other conductor means projecting into the envelope, and means supporting said circuit structure on the last mentioned conductor means.

22. An electronic tube comprising an envelope, a plurality of anodes in the envelope, heat radiating fins on said'anodes, a grid adjacent each anode, anode conductor means projecting transversely into the envelope, means supporting the anodes on said conductor means, a grid circuit structure in the envelope comprising a pair of parallel legs extending longitudinally of said envelope, means supporting the grids on the intermediate portions of said circuit legs, other conductor means projecting into the envelope, and means supporting said circuit structure on the last mentioned conductor means.

23. Ari-electronic tube comprising anenvelope, a plurality of anodes in the envelope, a grid adja-' cent each anode an' anode lead means project inginto theenvelope, means unitarily-support ing the anodes on said lead means, a grid circuit structure in the envelope, means. supporting the grids on the circuit structure, other leads projecting into the envelope, and means supporting said circuit structure on the last mentioned leads.

24. An electronic tube comprising an envelope, a plurality of pairs of anodes in the envelope, fins on the anodes, certain of the fins being common to a pair of the anodes and others of the fins being common to another pair of anodes, a grid adjacent each anode, anode conductor means projecting into the envelope, means supporting the anodes on said conductor means, a grid circuit structure in the envelope, means supporting said grids on the circuit structure, other conductor means projecting into the envelope, and means supporting said circuit structure on the last mentioned conductor means.

25. An electronic tube comprising an envelope, a set of at least four anodes in the envelope, means interconnecting as a unit all of the anodes in said set, a grid adjacent each anode, anode conductor means projecting into the envelope, means supporting the anodes on said conductor means, a grid circuit structure in the envelope, means supporting said grids on the circuit structure, other conductor means projecting into the envelope, and means supporting said circuit structure on the last mentioned conductor means.

26. An electron tube comprising an envelope having therein an anode assembly and an anode tuning conductor of metallic ribbon material having a width substantially equal to a dimension of said anode assembly, said ribbon being l4 bonded'along substantially its entire width to said anode assembly, said conductor having a largev surface area whereby it constitutes an efiective heat radiating means for said anode assembly.

HAROLD A. ZAHL.

REFERENCES CITED The following references are of record in the file of this patent:

' I UNITED STATES PATENTS Number Name Date 1,605,735 Hough Nov. 2, 1926 1,693,258 Spaeth Nov. 27, 1928 1,713,615 0111 May 21, 1929 1,743,629 Spaeth Jan. 14, 1930 1,750,386 Brown Mar. 11, 1930 1,832,288 Faigl Nov. 17, 1931 1,853,632 Mouromtsefi Apr. 12, 1932 1,979,668 Boddie Nov. 6, 1934 1,981,058 Marconi et a1 Nov. 20, 1934 1,997,019 Schloemilch Apr. 9, 1935 2,021,891 Hollmann Nov. 26, 1935 2,096,459 Kassner Oct. 19, 1937 2,105,026 Dallenbach Jan. 11, 1938 2,190,668 Llewellyn Feb. 20, 1940 2,203,249 Bohme June 4, 1940 2,228,939 Zottu et a1. Jan. 14, 1941 2,239,303 Purington Apr. 22, 1941 2,401,059 Eitel et a1 Mar. 28, 1946 

